Sparrowvsrevolution writes: In the wake of Syria’s 52-hour digital blackout last week, the networking firm Renesys performed an analysis of which countries are most susceptible to an Internet shutdown, based simply on how many distinct entities control the connections between the country’s networks and those of the outside world. It found that for 61 countries and territories, just one or two Internet service providers maintain all external connections–a situation that could make possible a quick cutoff from the world with a well-placed government order or physical attack.

Another 72 countries have between three and ten providers that link to the outside world, a situation that makes a cutoff harder but by no means impossible. Egypt managed to black out its Internet last year despite having seven ISPs with external connections, though it took several days for it to track down and cut off all seven.